CVE-2026-73450
Security Advisory 0161
CVSS Score
6.9
EPSS Score
0.0%
EPSS Percentile
0th
On affected platforms running Arista EOS with MLAG Dual Primary Detection configured, an unauthenticated attacker with access to the Dual Primary Detection network segment can send specially crafted packets to interfere with the dual-primary state. If the MLAG primary switch fails while these packets are present, the secondary switch incorrectly concludes it is in a dual-primary condition and err-disables its interfaces, leading to a traffic interruption.
| CWE | CWE-345 |
| Vendor | arista networks |
| Product | eos |
| Published | Sep 16, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:H Attack Vector
Adjacent
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Changed
Confidentiality
None
Integrity
Low
Availability
High
Affected Versions
Arista Networks / EOS
4.36.0 ≤ 4.36.1F 4.35.0 ≤ 4.35.5M 4.34.0 ≤ 4.34.7.1M 4.33.0 ≤ 4.33.9M 0.0.0 < 4.33.0
References
Credits
This issue was discovered internally by Arista, and the company is not aware of any malicious exploitation of this vulnerability in customer networks.